Ultraviolet radiation has been implicated in the etiology of cutaneous melanoma and other skin cancers and may be involved in the development of eye diseases including uveal melanoma and cataracts. Optimal methods for assessing the damage to skin due to sunlight, which avoid the recall and measurement problems of questionnaires and the feasibility problems of skin biopsies, have yet to be demonstrated. Holman and colleagues have demonstrated that actinic skin damage as assessed by cutaneous microtopography (dental impression) is reliable measured and strongly related both to risk of cutaneous melanoma and non-melanoma skin cancer. The proposed study will assess site-to-site variability in microtopography, evaluate behavioral and constitutional determinants of site-to-site variability and examine the feasibility of performing microtopography by mail. Two hundred patients being seen for retinal diseases will have microtopography performed on a sun-exposed area of the hard, an area under the arm relatively unexposed to sun, and on the cheek. Also at the time they are seen, they will be interviewed about their sunlight-related behaviors and personal characteristics. To assess the feasibility of completing microtopography by mail, two to three months before their clinic visit, 100 of these patients will be asked to complete by mail a microtopograph of the hand. An additional 100 adults, identified by sampling from randomly selected towns, will be interviewed by telephone about their sunlight exposures and will also be asked to complete by mail a microtopograph of the same site. This study will be relevant for developing a procedure with potential for improving the quality of epidemiologic studies thought to be related to ultraviolet exposure. Results will determine the correspondence of microtopography of the hand (the standard site) with microtopography of the face near the eye (more relevant for eye disease) and a sun-exposed sits (relevant for determining the validity of the measure). Modification of actinic damage to the face attributable to wearing eyeglasses or sunglasses, using makeup or sunscreen, or wearing hats with brims will be evaluated. If susceptibility to damage from the sun and sunlight-related behaviors are independent predictors of the difference in microtopography grade between sun-exposed and sun-unexposed sites, this will be additional evidence for the validity of microtopography. The study will also determine whether it is feasible to obtain this relatively inexpensive measurement of cumulative sunlight damage by mail in a large cohort.